Whether a small business is looking for e-mail, computing power or storage on the cloud, there are a host of companies ready and waiting to serve. Cloud computing services are exploding in popularity and it hasn’t gotten lost on the heavy hitters in the tech world .

With all the different options to choose from, it can be overwhelming for small business owners to determine which provider is the right fit for their needs.

Here’s a breakdown of five cloud providers and what they have to offer:

Office 365

The latest arrival to the cloud party is from Microsoft, which unveiled Office 365 just a few weeks ago.

For $6 a month, small businesses get access to all of Microsoft’s Office (MSFT) applications without having to install the software on their computers or servers. Office 365 users can access e-mail, documents, contacts and calendars from any device that’s connected to the Internet.

According to Microsoft, the $6- a-month plan is suitable for companies that have less than 25 employees and do not have an IT staff on payroll. Under this plan, companies get a 25-GB mailbox, the ability to share calendars and view multiple calendars side by side and business-class security that protects from spam and viruses.

Another perk: Small business owners and employees can work simultaneously on documents and spreadsheets and see in real time who is editing and viewing documents and spreadsheets. Small businesses also get access to instant messaging, PC-to-PC audio and video calls and online meetings.

Amazon Web Services

Many small businesses don’t have the desire, space or financial ability to house servers and storage devices on site, which makes offerings like Amazon’s Web Services popular.

Instead of having to buy hardware equipment, small businesses can pay a monthly fee to access Amazon’s infrastructure in the cloud, allowing them to order computing power and storage on an as-needed basis.

Amazon.com (NASDAQ: AMZN) offers packages tailored to users that want total control over the cloud and for those that would rather let Amazon handle it all. Amazon.com touts its cloud service gives small businesses the ability to add and remove processing power and storage in real time and provides access to multiple levels of security to ensure data safety.

Google Apps for Small Businesses 

Being long-time competitors, it is no surprise that Google and Microsoft have similar offerings in the cloud. Google’s (NADAQ: GOOG) service is a year older and dollar cheaper per month than Microsoft’s offerings. 

Just like with Office 365, all of the applications are hosted online, which reduces IT costs for businesses since it eliminates maintenance costs as well as software and server upgrades. 

Small business users of Google Apps pay $5 a month per user after a 30-day free trial. The monthly fee gives users customized e-mail addresses, mobile e-mail, a calendar, IM access, spam filtering, Google Docs, Google Sites (which lets the small business create Web pages), 24/7 e-mail and phone support and a guarantee of 99.9% uptime.

Apple’s iCloud

Think of Apple’s iCloud as an online hard drive on steroids.

Set to come out this fall, iCloud will allow small business owner to store music, apps, photos, documents and any other data online and pushes it out wirelessly to all of a small businesses' devices whether it’s a laptop, smartphone or iPad. ICloud also keeps e-mail, contacts and calendars up to date on chosen devices, no syncing required.

With iCloud, a user can also view and edit the same document on whatever device is in use at that particular time. For app-happy users, iCloud enables apps to be downloaded to each Apple device with no extra charge and push newly-purchased apps to all of the devices. Users who sign up for iCloud also get 5 GB of free storage.

Dropbox.com

Dropbox isn’t a household name yet, but this cloud storage provider is getting a lot of attention, particularly from venture capitalists looking to fund the next technology darling.

Dropbox.com lets users store files on its secure Web site that can be accessed via Windows, Mac, Linux, iPad, iPhone, and Android and BlackBerry phones. The service is free for 2GB of storage, $9.99 a month for 50GB of storage and $19.99 a month for a 100GB of storage. The service even works when a user is offline, eliminating the constraints of needing an Internet connection. Users have the option of only transferring parts of a file and can manually set bandwidth limits so Dropbox doesn’t hog the Internet connection. Users can also share folders to work on projects and documents together, which can be particularly appealing to small business owners.